The Manhattan project had profound impacts on a variety of Native communities ranging from Wanapum, Nez Perce, Yakama, and Umatilla tribal nations who were impacted by the Hanford site in Washington state to the Navajo Nation and pueblo nations in the southwest who were impacted by uranium mining and Los Alamos National Laboratory. 

Tribal nations were displaced from their homelands for the construction of these facilities and were often denied access to their homelands both throughout the project and to the present day. Ongoing environmental contamination has continued to affect the health of tribal members and the health of the land. Contamination and exploitation of tribal natural resources and homelands is an ongoing and everpresent concern of settler-colonial development, including capitalist exploitation of resources; industrial air, water and soil pollution; and weapons development. These strategies are a product of continued US attempted extermination and genocide of Indigenous peoples. Settler-colonial nations often use environmental pollution as a means of severing Indigenous people from their land.

Issues of environmental justice are deeply entangled with the legacy of the Manhattam Project. The National Park Service's (NPS) document, "African Americans at Los Alamos and Oak Ridge: A Historic Context Study" rightfully brings attention to these issues, pointing out that "historically, minority and low-income groups have been disproportionately affected by the environmental impacts of large-scale development by the government, military, and sometimes private entities." NPS brings attention to the reality that the majority of the Manhattan Project’s main facility locatoins selected in part due to the demographic of marginalized populations that resided in the area. In northern New Mexico, where Los Alamos was constructed, the community is largely American Indian Pueblo tribal members and Hispanic homesteaders. In eastern Tennessee, where Oak Ridge National Laboratory sits, community members include poor farmers and coal miners. At the Hanford site in eastern Washington, the surrounding community was composed largely of American Indians and small agricultural communities.

National Park Service, "African Americans at Los Alamos and Oak Ridge: A Historic Context Study," National Park Service Department of the Interior, 65 (2019), https://www.nps.gov/mapr/learn/historyculture/upload/Study-African-Amer…;